Multicarrier techniques for wireless systems

ABSTRACT

Multicarrier techniques for wireless communications system are described. An apparatus may comprise a carrier management module to define a primary carrier for use by a multicarrier communications system to communicate control information, and a secondary carrier for use by the multicarrier communications system to communicate media information, with the secondary carrier having a communication parameter and technology that is potentially different from the primary carrier. Other embodiments are described and claimed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation claiming the benefit of, and priorityto, previously filed U.S. patent application Ser. No. 13/706,275 filedDec. 5, 2012, which is a continuation of U.S. patent application Ser.No. 13/269,013 filed Oct. 7, 2011, both entitled “MulticarrierTechniques for Wireless systems,” which is a continuation of patentapplication Ser. No. 11/748,310 filed May 14, 2007, entitled “Method AndApparatus For Multicarrier Communication In Wireless Systems”. All ofthe above are incorporated herein by reference in their entirety.

BACKGROUND

With ever growing demand for mobile broadband data services and ashortage of contiguously large portions of the radio-frequency (RF)spectrum for deployment, next generation broadband wireless accessnetworks may be deployed with fewer RF spectrum resources. Furthermore,as the systems are deployed and the need for higher data rates arises,the performance demands of the broadband wireless access networks mayincrease. For example, streaming broadband video requires significantamounts of bandwidth that is increasingly difficult to provide with thelimited RF spectrum resources typically assigned to a wirelesscommunications system. In addition, more users are migrating towardswireless communications systems for their communications services,thereby increasing system load and further decreasing the bandwidthavailable to any one user or the collective system overall.Consequently, there may be a substantial need to improve performance ofwireless communication systems by more efficiently using the RF spectrumavailable to a device, network or system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates one embodiment of a network.

FIG. 2 illustrates one embodiment of network data flow.

FIG. 3 illustrates one embodiment of a communications system.

FIG. 4 illustrates one embodiment of a logic flow.

DETAILED DESCRIPTION

Various embodiments are generally directed to improvements for wirelesscommunications systems. Some embodiments are particularly directed totechniques for improving RF spectrum utilization by multicarriercommunications systems. Examples of multicarrier communication systemsinclude without limitation systems compliant with various Institute ofElectrical and Electronics Engineers (IEEE) standards, such as the IEEE802.11 standards for Wireless Local Area Networks (WLANs), the IEEE802.16 standards for Wireless Metropolitan Area Networks (WMANs), andthe IEEE 802.20 or Mobile Broadband Wireless Access (MBWA), amongothers. For example, the Worldwide Interoperability for Microwave Access(WiMAX) is a wireless broadband technology based on the IEEE 802.16standard of which IEEE 802.16-2004 and the 802.16e amendment(802.16e-2005) are Physical (PHY) layer specifications.

Various embodiments attempt to increase effective bandwidth by usingdata aggregation techniques across multiple carriers to provide variablebandwidth for multicarrier communications systems. The data aggregationmay be accomplished across a heterogeneous mix of contiguous ornon-contiguous RF spectrum. Further, the data multicarrier operation maybe accomplished across a heterogeneous mix of communication technologiesand equipment operating in different bandwidths and duplexing methods.The multicarrier data aggregation effectively creates wider bandchannels with higher peak throughput, while supporting a mix of legacylow bandwidth and the new multicarrier terminals. The multicarrier dataaggregation may be used in the downlink and/or uplink asymmetricallybased on system load and peak rate or Quality of Service (QoS) demand.The proposed multicarrier enhancements also allow load sharing acrossmultiple carriers.

Various embodiments are directed to multicarrier management techniquesto define multiple types of channels or carriers for a multicarriercommunications system. The first or primary carrier may comprise of allcommon control channels to communicate control information as well asuser data. The second or secondary carrier may mainly comprise of datachannels to communicate media information, with minimal or no supportfor signaling. In some cases, multiple primary carriers may be used fora single secondary carrier. Similarly, multiple secondary carriers maybe used for a single primary carrier. The number of primary carriers andsecondary carriers may increase or decrease depending upon the bandwidthneeded for a given client, such as a device, network or system. Forexample, the more bandwidth a client needs the greater the number ofavailable secondary carriers may be created and aggregated to providethe requisite bandwidth. Conversely, the less bandwidth a client needsthe fewer the number of available secondary carriers are needed toprovide the requisite bandwidth. In the latter case, reducing the numberof primary or secondary carriers may release or free RF spectrumresources for use by another client. In this manner, a generalmulticarrier architecture or scheme may service a given client accordingto the particular needs of the client and in view of a totalavailability of RF spectrum resources.

Various embodiments may also dynamically vary bandwidth for a clientbased on client needs or resource availability. The instantaneousbandwidth demands of a given client may vary over time. The available RFspectrum to provide such bandwidth may also vary over time based on ahost of factors, not the least of which is an instantaneous number ofclients using RF resources and the particular bandwidth demands forthose clients. Consequently, some embodiments may attempt to dynamicallyor semi-dynamically balance bandwidth assignments over time based onclient demands and RF resource availability. Accordingly, someembodiments may dynamically allocate or release channels or carriers toaccommodate changes in bandwidth demands for a given client, whetherthat client is a device, network or entire system.

FIG. 1 illustrates one embodiment of a network 100. The network 100 maycomprise multiple nodes, such as nodes 110, 130. A node generally maycomprise any physical or logical entity for communicating information inthe network 100 and may be implemented as hardware, software, or anycombination thereof, as desired for a given set of design parameters orperformance constraints. Although FIG. 1 may show a limited number ofnodes by way of example, it can be appreciated that more or less nodesmay be employed for a given implementation.

In various embodiments, the nodes 110, 130 may be arranged tocommunicate control information and media information over wirelessshared media 140. In the illustrated embodiment, the node 110 maycomprise a wireless transmitter node designated as a source (S) node,and the node 130 may comprise a wireless receiver node designated as adestination (D) node. A more detailed block diagram and description forthe nodes 110, 130 are provided below with reference to FIGS. 3 and 4.

In various embodiments, the S node 110 may represent any transmittingnode. In one embodiment, for example, the S node 110 may represent anetwork point of attachment. A network point of attachment may compriseany device capable of acting as a communication hub for wireless clientdevices to connect to a wired network from a wireless network. Networkpoints of attachment may include, but are not necessarily limited to, awireless access point (AP), a WiFi or WLAN AP (e.g., hotspots), a WiMAXwireless broadband base station, a cellular base station, a mobilesubscriber center, a radio network controller, a router, a switch, abridge, a gateway, and any other device capable of acting as acommunication hub for wireless client devices to connect to a wirednetwork from a wireless network and to extend the physical range ofservice of a wireless network. The embodiments are not limited in thiscontext.

In one embodiment, for example, the D node 130 may represent anyreceiving node. In one embodiment, for example, the D node 130 mayrepresent a wireless client device. A wireless client device may includeany electronic device having wireless capabilities, including aprocessing system, a computer system, a computer sub-system, a computer,an appliance, a workstation, a terminal, a server, a personal computer(PC), a laptop, an ultra-laptop, a handheld computer, a personal digitalassistant (PDA), a set top box (STB), a telephone, a mobile telephone, acellular telephone, a handset, a subscriber station (SS), amicroprocessor, an integrated circuit such as an application specificintegrated circuit (ASIC), a programmable logic device (PLD), aprocessor such as general purpose processor, a digital signal processor(DSP) and/or a network processor, and so forth. The embodiments are notlimited in this context.

It is worthy to note that although a given node 110, 130 may bedesignated a transmitting node or receiving node in various embodimentsby way of example, such designations are provided for sake of clarityand not limitation. It may be appreciated that either node 110 or 130may comprise a transmitting node or receiving node. In some cases, thenodes 110, 130 may each comprise both a transmitting node and areceiving node. For example, the nodes 110, 130 may each be equippedwith a wireless transmitter/receiver (“transceiver”), along withassociated wireless equipment typically implemented for a wirelesscommunication device (e.g., antennas, amplifiers, filters, processors,and so forth), thereby providing both nodes 110, 130 with transmittingand receiving capabilities.

In various embodiments, the nodes 110, 130 may include respectivewireless transceivers or radios 160, 164. The radios 160, 164 may becompliant with one or more wireless communication standards, such asstandards promulgated by IEEE, the Internet Engineering Task Force(IETF), the International Telecommunications Union (ITU), the JointTechnical Committee (JTC) of European Telecommunications StandardsInstitute (ETSI), the European Committee for ElectrotechnicalStandardization (CENELEC), the European Broadcasting Union (EBU), and soforth. In various embodiments, the radios 160, 164 may be compliant withone or more IEEE 802.XX standards including IEEE 802.11 standards (e.g.,802.11a, b, g/h, j, n, and variants), the IEEE 802.16 standards (e.g.,802.16-2004, 802.16.2-2004, 802.16e-2005, 802.16f, and variants), theIEEE 802.20 standards and variants, and so forth. In variousembodiments, the radios 160, 164 may also be compliant with one or moreDigital Video Broadcasting (DVB) standards including the ETSI DigitalVideo Broadcasting Terrestrial (DVB-T) broadcasting standards andvariants, the DVB Handheld (DVB-H) broadcasting standards and variants,the Digital Multimedia Broadcasting (DMB) broadcasting standards andvariants. The embodiments are not limited in this context.

In various embodiments, the radios 160, 164 may communicate informationover wireless shared media 140. The wireless shared media 140 maycomprise one or more allocations of RF spectrum. The allocations of RFspectrum may be contiguous or non-contiguous. The radios 160, 164 maycommunicate information over the wireless shared media 140 using variousmulticarrier techniques utilized by, for example, WiMAX or WiFi systems.For example, the radios 160, 164 may utilize MIMO techniques to performbeam forming, spatial diversity or frequency diversity, as described inmore detail with reference to FIG. 3.

In various embodiments, the nodes 110, 130 may include respectivecarrier management modules 162, 166. The carrier management modules 170,174 may be generally arranged to define multiple types of channels orcarriers for a multicarrier communications system. A first type maycomprise a primary carrier to operate as a control channel tocommunicate control information as well as user data. A second type maycomprise a secondary carrier to operate as a media or data only channelto communicate media information. By separating the control channel fromthe media only channel, the network 100 has greater flexibility indynamically assigning large portions of the RF spectrum to givenclients. For example, a client may monitor the control channel toreceive configuration parameters for any changes made to the mediachannel, and vice-versa. Having multiple channels ensures a greaterprobability that channel modifications are propagated to the affectedclients. Defining different types of carriers provides other advantagesas well, which are discussed in more detail later. It is worthy to notethat although various embodiments may discuss certain multicarriermanagement operations with reference to both the carrier managementmodules 170, 174, it may be appreciated that some or all of themulticarrier management operations may be performed by the carriermanagement module 170, the carrier management module 174, or acombination of both carrier management modules 170, 174.

In one embodiment, the carrier management modules 170, 174 may bearranged to define one or more primary carriers 142-1-m for use by themulticarrier communications system. The primary carriers are designed tocommunicate primarily control information, and in some cases limitedmedia information. Control information may refer to any datarepresenting commands, instructions or control words meant for anautomated system. For example, control information may be used to routemedia information through a system, or instruct a node to process themedia information in a predetermined manner. In one embodiment, forexample, the control information may include the full range of mediaaccess control (MAC) messaging, signaling plane messaging, control planemessaging, and so forth. For example, a primary carrier may be used toprovide all broadcast and common control messaging to the clientdevices, including control messages needed to manage client statetransitions, such as transitioning from an active mode to a sleep modeor idle mode. Although the primary carriers are designed to communicatecontrol information, however, one or more primary carriers may also beused to communicate media information as needed by the network 100.

In various embodiments, the carrier management modules 170, 174 may bearranged to define multiple primary carriers. For example, when thenumber of users in a given sector is relatively large, the carriermanagement modules 170, 174 may define multiple primary carriers anddefine an algorithm to semi-statically distribute users and theirMAC/signaling traffic across the multiple primary carriers. The userscan select and attach to different primary carriers based on their MACaddress or other hardware identification numbers, or randomly choose oneof the available primary carriers.

In one embodiment, for example, the carrier management modules 170, 174may be arranged to define one or more secondary carriers 144-1-n for useby a multicarrier communications system. The secondary carriers aredesigned to communicate primarily media information, and in some caseslimited control information. Media information generally may refer toany data representing content meant for a user, such as imageinformation, video information, graphical information, audioinformation, voice information, textual information, numericalinformation, alphanumeric symbols, character symbols, and so forth. Forexample, the secondary carriers would be suitable for broadcastingstreaming video information or downloading large data files. Thesecondary carriers would typically communicate only a preamble,optionally few broadcast indicators, and the remainder user data.Optionally, some or all signaling and MAC messages may also betransmitted on secondary carriers as needed by the network 100.

In various embodiments, the carrier management modules 170, 174 may bearranged to define multiple secondary carriers. For example, the morebandwidth a client needs the greater the number of available secondarycarriers may be created and aggregated to provide the requisitebandwidth. Conversely, the less bandwidth a client needs the fewer thenumber of available secondary carriers are needed to provide therequisite bandwidth. In the latter case, reducing the number of primaryor secondary carriers may release or free RF spectrum resources for useby another client. As a result, the multicarrier data aggregation acrossmultiple secondary carriers effectively creates wider band channels withhigher peak throughput for the network 100.

In various embodiments, the secondary carrier may have a communicationparameter different from the primary carrier. Examples of communicationparameters may include values representing a channel bandwidth, aduplexing mode, a spectrum allocation, a downlink-to-uplink ratio, andother measurable communications system characteristic. For example, theprimary carrier may provide a channel bandwidth of 5 MHz, while thesecondary carrier provides a channel bandwidth of 40 MHz. In anotherexample, the primary carrier may utilize a Time Division Duplex (TDD)mode, while the secondary carrier provides Frequency Division Duplex(FDD) mode. In yet another example, the primary carrier may utilize afirst RF spectrum allocation, while the secondary carrier utilizes asecond RF spectrum allocation. As previously described, the first andsecond RF spectrum allocations may be contiguous or non-contiguousrelative to each other. In still another example, the downlink-to-uplinkbandwidth ratio may vary or be asymmetric. For example, the downlinkbandwidth may be relatively large to receive streaming video, while theuplink bandwidth is relatively small to receive user selections. It isworthy to note that the communication parameters and values describedabove are by way of example and not limitation, and that any number ofcommunication parameters and values may be used for a givenimplementation based on a given set of design and performanceconstraints. The embodiments are not limited in this context.

In various embodiments, the ratio of primary carriers to secondarycarriers may vary. In some embodiments, the ratio of primary carriers tosecondary carriers is symmetric, where there is a single primary carrierfor each secondary carrier and vice-versa. In some embodiments, theratio of primary carriers to secondary carriers is asymmetric, wherethere are multiple primary carriers for each secondary carrier, multiplesecondary carriers for each primary carrier, or multiple primarycarriers for multiple secondary carriers.

In one embodiment, for example, the nodes 110, 130 may use the definedprimary carriers and secondary carriers to communicate respectivecontrol information and media information via respective radios 160,164. By defining two separate types of carrier classes, however, thenodes 110, 130 may also use the multiple carrier classes as redundancyor backup communication channels. For example, if the bandwidth demandfor the secondary carriers is greater than the bandwidth availabilityprovided by the secondary carriers, then the nodes 110, 130 may use oneor more of the primary carriers to handle overflow data traffic toeffectively increase instantaneous peak throughput. In another example,if the primary carrier is impaired or lost due to reducedsignal-to-noise ratio (SNR), congestion, cross-talk, and a myriad ofother factors affecting channel quality or throughput for wirelesssystems, then the nodes 110, 130 may use one or more secondary carriersto communicate control information to the clients. In yet anotherexample, if the nodes 110, 130 may dynamically change the definitionsfor the primary carriers or secondary carriers, the nodes 110, 130 mayuse one carrier to propagate the changes made to the other carrierwithout having the nodes 110, 130 lose connectivity.

In various embodiments, the carrier management modules 170, 174 may bearranged to dynamically modify a communication parameter for a primarycarrier or a secondary carrier based on a system performance parameter.Examples of system performance parameters may include valuesrepresenting a system load, a system peak rate, a priority, a QoS, orother performance characteristic. For example, changes in system load orclient/traffic priority may affect the amount of channel bandwidthavailable to a given client. In this case, the carrier managementmodules 170, 174 may allocate or release various primary and/orsecondary carriers to increase or decrease bandwidth accordingly. Inanother example, changes in QoS demands may affect the particular RFspectrum allocated to a primary or secondary carrier. These are merely afew examples, and it may be appreciated that any number of communicationparameters and/or system performance parameters and their relationshipsmay be defined for a given implementation.

In various embodiments, the carrier management modules 170, 174 may bearranged to define the primary carrier with a first portion of a RFspectrum, and the secondary carrier with a second portion of the RFspectrum. In this manner, the carrier management modules 170, 174facilitate data aggregation across a heterogeneous mix of contiguous ornon-contiguous RF spectrum. In one embodiment, the first portion andsecond portion may comprise contiguous RF spectrum. For example, a WiMAXsystem may have allocated spectrum in the 1.9-2.6 GHz range. A primarycarrier may utilize a first portion of the available RF spectrum in the2.5-2.6 GHz range, while the secondary carrier may utilize a secondportion of the available RF spectrum in the 2.6-2.7 GHz range, with theappropriate guard bands. In one embodiment, the first portion and secondportion may comprise non-contiguous radio frequency spectrum. Forexample, a primary carrier may utilize a first portion of the availableRF spectrum in the 1.9-2.0 GHz, and the secondary carrier may utilize asecond portion of the available RF spectrum in the 2.5-2.7 GHz range. Insome cases, the first portion and the second portion may partiallyoverlap. The embodiments are not limited in this context.

FIG. 2 illustrates one embodiment of network data flow 100. The networkdata flow 100 represents a data flow for messaging provided over aprimary carrier 142 (RF1) and a secondary carrier 144 (RF2). As shown inFIG. 2, a S node 110 may send some control information to D node 130over wireless shared media 140 using both carriers 142, 144. Forexample, the S node 110 may send control information over both carriers142, 144 in the form of respective preambles 210, 220 at t₁. The S node110 may further send broadcast messaging/indicators 212, 222 overrespective carriers 142, 144 at t2. The S node 110 may also send acommon messaging 214 over the primary carrier 142 at t2. The commonmessaging 214 may provide downlink (DL) allocations 216, 226 and uplink(UL) allocations 218, 228 for respective carriers 142, 144. The S node110 may then communicate with the D node 130 by sending additionalcontrol information via the primary carrier 142, and media informationvia the secondary carrier 144, at time t3 and moving forward.

In various embodiments, the nodes 110, 130 may be arranged tocommunicate control information over the primary carrier 142 and mediainformation over the secondary carrier 144 using the respective radios160, 164. In some cases, however, a node may include multiple radios,with each radio utilizing the same or a different bandwidth, duplexingor communication technology as the primary carrier. Consequently, thecarrier management modules 170, 174 may facilitate data aggregationacross a heterogeneous mix of carriers. In this case, the multicarrierscheme can be used for a mix of different terminals with differentcapabilities as shown in Table 1 as follows:

TABLE 1 Device Type Capabilities Type 0 Legacy devices, no multiplecarriers support Type 1 Single contiguous Band, Multiple Carriers butSingle Carrier at a time Type 2 Single contiguous Band, Multiple CarrierDevice (TX and/or RX) Type 3 Multiple non-contiguous bands, Carriers butSingle Carrier at a time Type 4 Multiple non-contiguous bands, MultipleCarrier Device (TX and/or RX)

With reference to Table 1, in general the associated MAC and signalingmessages during the data traffic exchanges (e.g., link adaptation, HARQACK/NAK and channel quality feedback) can be transmitted in the samecarrier in which data is sent. Alternatively, and if multiplesimultaneous carriers are supported (Types 2, 4), such messages can becombined for all carriers and sent on the primary carrier 142. Tosupport Types 1, 3, in addition to the data and associated MACsignaling, the secondary carrier 144 will also include broadcastnotifications to ensure that the device directed to a secondary carrier144 can be directed back to primary carrier 142 if there is urgentmessage to be delivered to them. The broadcast notifications on thesecondary carriers 144 can be binary indicators, for example, to whichterminals will hash based on a MAC address or self-contained andaddressed MAC messages. All Type 1 and 3 terminals directed to asecondary carrier 144 should monitor such broadcast notifications forthe frame during which they use that secondary carrier 144.

The availability of heterogeneous radio technologies presents additionalopportunities to flexibly allocate bandwidth for a multicarriercommunication system. For example, some embodiments may extend themulticarrier scheme to enable Layer 2 or Layer 3 coupling of a primaryOFDMA based technology deployed in the primary carrier 142, in this caseWiMAX II, with an alternative radio co-located and deployed on thesecondary carrier. The coupling may be accomplished at the signaling andMAC layer depending on the specific design of the alternative technologyused for the second carrier. One example of this coupling and itbenefits can be shown with a mix of WiMAX and DVB-H technology. In thiscase, the primary carrier 142 is used for all unicast and some multicastservices, while allocating large blocks of video broadcasting on asecondary broadcast only WiMAX or DVB-H secondary carrier 144.Consequently, the client state is managed by the WiMAX network, whilebroadcast content is delivered on a broadcast optimized system. Thislevel of coupling allows the user to receive data from either or bothcarriers without losing its power saving capability.

Referring again to FIG. 2, an S node 220 may include multiple physicallayer devices (PHY) 202-1-r. An example of a physical layer device mayinclude a radio that is compliant with a given air interface as definedby one or more standards or protocols. The S node 220 may berepresentative of, for example, the S node 110 with the addition ofmultiple radios (PHY 202-1-r). As shown in FIG. 2, the S node 220 mayinclude a first transmitter node (PHY 202-1) to communicate controlinformation over the primary carrier 142, and a second transmitter node(PHY 202-2) to communicate media information over the secondary carrier144. In various embodiments, the PHYs 202-1, 202-2 may be arranged touse different protocols. For example, the PHY 202-1 may comprise an IEEE802.16 compliant radio, while the PHY 202-2 may comprise an ETSI DVB-Hcompliant radio.

In various embodiments, the S node 220 may communicate with one or moreD nodes 210-1-s using the primary carrier 142 (RF1) and/or the secondarycarrier 144 (RF2). The D nodes 210-1-s may be representative of, forexample, the D node 130, some of which have multiple radios. Forexample, the D node (client 1) 210-1 may have a single PHY 204-1, whilethe D node (client 2) 210-2 may have PHYs 204-1, 204-2, and the D node(client 3) 210-3 may have PHYs 204-1, 204-3. It may be appreciated thatthe PHYs 204-1-s are designed to match corresponding PHYs 202-1-r inorder to properly transmit and receive information between the variousnodes.

As shown in FIG. 2, the D node 210-1 may have a PHY 204-1 to match thePHY 202-1 of the S node 220. Further, the PHY 204-1 of the D node 210-1may be arranged to operate using the primary carrier 142 (RF1) withinthe RF spectrum allocation of 10 MHz. In this example, the D node 210-1may be representative of a Type 0 device as described in Table 1, whichmeans it is a legacy device with no multiple carrier support.

As further shown in FIG. 2, the D node 210-2 may have PHYs 204-1, 204-2to match the respective PHYs 202-1, 202-2 of the S node 220. As with theD node 210-1, the PHY 204-1 of the D node 210-2 may be arranged tooperate using the primary carrier 142 (RF1) within the RF spectrumallocation of 10 MHz. In addition, the PHY 204-2 of the D node 210-2 maybe arranged to operate using the secondary carrier 144 (RF2) within theRF spectrum allocation of 20 MHz. In this case, the D node 210-2 may berepresentative of Type 2, 3 or 4 devices as described in Table 1.

As further shown in FIG. 2, the D node 210-3 may have PHYs 204-1, 204-3to match the respective PHYs 202-1, 202-3 of the S node 220. As with theD nodes 210-1, 210-2, the PHY 204-1 of the D node 210-3 may be arrangedto operate using the primary carrier 142 (RF1) within the RF spectrumallocation of 10 MHz. In addition, the PHY 204-3 of the D node 210-3 maybe arranged to operate using another secondary carrier 144 (RF3) withinthe RF spectrum allocation of 20 MHz. In this case, the D node 210-3 maybe representative of Type 2, 3 or 4 devices as described in Table 1.

In order to support the coordination and management of heterogeneousradios, some embodiments may utilize one or more special controlmessages to enable the multicarrier capabilities for the given airinterface technology. In one embodiment, for example, the carriermanagement modules 170, 174 may be arranged to generate and transmit anEnhanced Broadcast Channel Configuration (EBCC) messaging layer todefine a multicarrier channel configuration on the serving cell. TheEBCC messaging layer may be used to communicate various types of channelconfiguration information. For example, the EBCC messaging layer shouldbe used to communicate some or all of the types of information listed inTable 2 as follows:

TABLE 2 Type Examples Primary Carrier Parameters Carrier Index 1, 2, etcParameters Carrier Index Technology Type Carrier Parameters (ifdifferent than the Primary), including: Center Frequency Bandwidth FFTsize Frame Size DL/UL ratio Secondary Carriers List (only send CarrierIndex values if different than Primary) Technology Type CarrierParameters (if different than the Primary), including: Center FrequencyBandwidth FFT size Frame Size DL/UL ratio

In addition to EBCC signaling, traffic allocations should have theflexibility of pointing to data regions in the primary carrier and/orsecondary carriers. The allocations can be made to a single region inthe primary carrier or secondary carrier. The allocations can also pointto multiple data regions across multiple carriers at the same ordifferent sub-frames. Simultaneous allocations may also exist acrossmultiple carriers. For more effective vertical inter-technologyhand-offs, some embodiments can also define and advertise delta channelconfigurations for all primary carriers on neighboring base stations.This can include differences in technology type, center frequency,channel size, scanning rules, intervals, durations, triggers, and soforth.

In various embodiments, the carrier management modules 170, 174 mayallow substantially simultaneous aggregation of multiple carriers for afirst class of client devices, and switching between primary andsecondary carriers for a second class of client devices. Examples for afirst class of client devices may include higher end client terminalshaving radio capabilities for high-speed broadband communications, suchas WiMAX or WiMAX II client terminals. In this case, the carriermanagement modules 170, 174 may provide for data aggregation across agreater number of carriers to provide greater amounts of bandwidthappropriate to the communications capabilities of the client device.Examples for a second class of client devices may include lower endclient terminals having communications capabilities lower than the firstclass of client devices. In this case, the carrier management modules170, 174 may provide fast and seamless switching between primary andsecondary carriers to increase effective bandwidth utilization for therelatively limited communications resources of the second class ofclient devices.

FIG. 3 illustrates one embodiment of a communication system 300implementation of the network 100. FIG. 3 may illustrate, for example, ablock diagram of a system 300. System 300 may comprise, for example, acommunication system having multiple nodes, including nodes 110, 120,130. The node 120 is a wireless client device similar to the D node 130,and is included to merely represent that multiple client devices (Dnodes 120, 130) may be in communication with the S node 110 whilesimultaneously using portions of the primary carrier 142 and thesecondary carrier 144.

Embodiments of system 300 may include one or more fixed, stationary ormobile client devices and network points of attachment, such as thenodes 110, 120, 130 described with reference to FIG. 1. In oneembodiment, for example, the nodes 110, 120, 130 may comprise respectiveradios 160, 162, 164, as described with reference to FIG. 1. In variousembodiments, the radios 160, 162, 164 may each comprise WiFi, WiMAX,Bluetooth, Ultra-Wideband (UWB), and/or cellular compliant modules, orany combinations thereof, to communicate over respective wirelessnetworks, for example.

In one embodiment, system 300 nodes 110, 120, 130 may comprise fixedwireless devices. A fixed wireless device may comprise a generalizedequipment set providing connectivity, management, and control of anotherdevice, such as a mobile client device. Examples for nodes 110, 120, 130with fixed wireless devices may include a wireless AP, base station ornode B, router, switch, hub, gateway, and so forth. In otherembodiments, for example, nodes 110, 120, 130 may comprise WiFi WLAN AP,WiMAX broadband wireless base stations, among other technology APsand/or base stations for WLAN, WMAN, wireless personal area network(WPAN), wireless wide area network (WWAN), cellular, and others, forexample. Although some embodiments may be described with nodes 110, 120,130 implemented as a WiFi WLAN access point or WiMAX wireless broadbandbase station by way of example, it may be appreciated that otherembodiments may be implemented using other wireless devices andtechnologies as well. The embodiments are not limited in this context.

Operations for various embodiments may be further described withreference to the following figures and accompanying examples. Some ofthe figures may include a logic flow. It can be appreciated that anillustrated logic flow merely provides one example of how the describedfunctionality may be implemented. Further, a given logic flow does notnecessarily have to be executed in the order presented unless otherwiseindicated. In addition, a logic flow may be implemented by a hardwareelement, a software element executed by a processor, or any combinationthereof. The embodiments are not limited in this context.

FIG. 4 illustrates one embodiment of a logic flow 400. The logic flow400 may be representative of the operations performed by one or morenodes of the systems 100, 300, including the carrier management modules170, 174, for example. As shown in FIG. 4, the logic flow 400 may definea primary carrier and a secondary carrier for use by a multicarriercommunications system, the secondary carrier having a communicationparameter different from the primary carrier, at block 402. In somecases, the logic flow 400 may define multiple secondary carriers for theprimary carrier. In other cases, the logic flow 400 may define multipleprimary carriers for the secondary carrier. In still other cases, thelogic flow 400 may define multiple primary carriers for multiplesecondary carriers. The embodiments are not limited in this context.

As further shown in FIG. 4, the logic flow 400 may communicate controlinformation using the primary carrier and media information using thesecondary carrier at block 404. Alternatively, or substantiallysimultaneously, the logic flow 400 may communicate control informationusing the secondary carrier and media information using the primarycarrier.

In one embodiment, for example, a communication parameter for theprimary carrier or the secondary carrier may be dynamically modifiedbased on a system performance parameter. Examples of communicationparameters may include without limitation a channel bandwidth, duplexingmode, spectrum allocation, or downlink-to-uplink ratio value. Examplesof system performance parameters may include without limitation a systemload value, a system peak rate value, a priority value or a quality ofservice value. By way of example, the primary carrier may be initiallyassigned a first portion of RF spectrum, and the secondary carrier maybe initially assigned a second portion of RF spectrum. In some cases,the first portion and second portion may be contiguous RF spectrum, andin other cases non-contiguous RF spectrum. The carrier managementmodules 170, 174 may be implemented to monitor various systemperformance parameters, such as an instantaneous system load. If theinstantaneous system load rises above a threshold value, therebypotentially indicating that a relatively large number of wireless clientdevices are using the primary and secondary carriers, the carriermanagement modules 170, 174 may increase or decrease bandwidth for theprimary carriers or secondary carriers by creating or destroying somecarriers. This is merely one example, and many different types ofscenarios may be implemented in accordance with these principles.

In some cases, various embodiments may be implemented as an article ofmanufacture. The article of manufacture may include a storage mediumarranged to store logic and/or data for performing various operations ofone or more embodiments. Examples of storage media may include, withoutlimitation, those examples as previously described. In variousembodiments, for example, the article of manufacture may comprise amagnetic disk, optical disk, flash memory or firmware containingcomputer program instructions suitable for execution by a generalpurpose processor or application specific processor. The embodiments,however, are not limited in this context.

Various embodiments may be implemented using hardware elements, softwareelements, or a combination of both. Examples of hardware elements mayinclude any of the examples as previously provided for a logic device,and further including microprocessors, circuits, circuit elements (e.g.,transistors, resistors, capacitors, inductors, and so forth), integratedcircuits, logic gates, registers, semiconductor device, chips,microchips, chip sets, and so forth. Examples of software elements mayinclude software components, programs, applications, computer programs,application programs, system programs, machine programs, operatingsystem software, middleware, firmware, software modules, routines,subroutines, functions, methods, procedures, software interfaces,application program interfaces (API), instruction sets, computing code,computer code, code segments, computer code segments, words, values,symbols, or any combination thereof. Determining whether an embodimentis implemented using hardware elements and/or software elements may varyin accordance with any number of factors, such as desired computationalrate, power levels, heat tolerances, processing cycle budget, input datarates, output data rates, memory resources, data bus speeds and otherdesign or performance constraints, as desired for a givenimplementation.

Some embodiments may be described using the expression “coupled” and“connected” along with their derivatives. These terms are notnecessarily intended as synonyms for each other. For example, someembodiments may be described using the terms “connected” and/or“coupled” to indicate that two or more elements are in direct physicalor electrical contact with each other. The term “coupled,” however, mayalso mean that two or more elements are not in direct contact with eachother, but yet still co-operate or interact with each other.

It is emphasized that the Abstract of the Disclosure is provided tocomply with 37 C.F.R. Section 1.72(b), requiring an abstract that willallow the reader to quickly ascertain the nature of the technicaldisclosure. It is submitted with the understanding that it will not beused to interpret or limit the scope or meaning of the claims. Inaddition, in the foregoing Detailed Description, it can be seen thatvarious features are grouped together in a single embodiment for thepurpose of streamlining the disclosure. This method of disclosure is notto be interpreted as reflecting an intention that the claimedembodiments require more features than are expressly recited in eachclaim. Rather, as the following claims reflect, inventive subject matterlies in less than all features of a single disclosed embodiment. Thusthe following claims are hereby incorporated into the DetailedDescription, with each claim standing on its own as a separateembodiment. In the appended claims, the terms “including” and “in which”are used as the plain-English equivalents of the respective terms“comprising” and “wherein,” respectively. Moreover, the terms “first,”“second,” “third,” and so forth, are used merely as labels, and are notintended to impose numerical requirements on their objects.

Although the subject matter has been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described above.Rather, the specific features and acts described above are disclosed asexample forms of implementing the claims.

1. A wireless communication device, comprising: a processor; and acarrier management module for execution by the processor to performcarrier aggregation of multiple carriers to provide variable bandwidthfor a multicarrier communications system comprising an orthogonalfrequency division multiple access (OFDMA) system, each carrier toutilize a different portion of radio frequency spectrum, with a numberof carriers for carrier aggregation to increase or decrease based on anamount of bandwidth needed by a client device.
 2. The wirelesscommunication device of claim 1, the carrier management module toaggregate a primary carrier and a secondary carrier, each of the primarycarrier and the secondary carrier arranged to communicate controlinformation, media information, or control information and mediainformation.
 3. The wireless communication device of claim 2, theprimary carrier to utilize a first portion of the radio frequencyspectrum for use by the multicarrier communications system, and thesecondary carrier to utilize a second portion of the radio frequencyspectrum for use by the multicarrier communications system, wherein thefirst and second portions comprise contiguous radio frequency spectrums.4. The wireless communication device of claim 2, the primary carrier toutilize a first portion of the radio frequency spectrum for use by themulticarrier communications system, and the secondary carrier to utilizea second portion of the radio frequency spectrum for use by themulticarrier communications system, wherein the first and secondportions comprise non-contiguous radio frequency spectrums.
 5. Thewireless communication device of claim 2, the primary carrier and thesecondary carrier having a different communication parameter.
 6. Thewireless communication device of claim 2, the primary carrier to utilizea time division duplex (TDD) mode.
 7. The wireless communication deviceof claim 2, the primary carrier to communicate hybrid automatic repeatrequest (HARQ) signals.
 8. The wireless communication device of claim 2,the primary carrier to communicate uplink information.
 9. The wirelesscommunication device of claim 2, the carrier management module toaggregate another secondary carrier with the primary carrier and thesecondary carrier to further increase effective bandwidth for themulticarrier communications system.
 10. The wireless communicationdevice of claim 1, comprising a wireless transceiver to communicatecontrol information over a first carrier and media information over asecond carrier using orthogonal frequency division multiplexing symbols.11. A system, comprising: a node to increase effective bandwidth for amulticarrier communications system by performing aggregation acrossmultiple carriers to provide variable bandwidth for the multicarriercommunications system, the node comprising: an antenna array; a radio toconnect to the antenna array; and a carrier management module to connectto the radio, the carrier management module to aggregate a primarycarrier and multiple secondary carriers for a multicarriercommunications system, the primary carrier arranged to communicateprimarily control information and limited media information, thesecondary carriers arranged to communicate primarily media informationand limited control information.
 12. The system of claim 11, the primarycarrier and the secondary carriers to utilize different portions of aradio frequency spectrum of the multicarrier communications system,wherein the different portions comprise contiguous radio frequencyspectrums.
 13. The system of claim 11, the primary carrier and thesecondary carriers to utilize different portions of a radio frequencyspectrum of the multicarrier communications system, wherein thedifferent portions comprise non-contiguous radio frequency spectrums.14. The system of claim 11, the primary carrier and the secondarycarriers having a different communication parameter.
 15. The system ofclaim 11, the primary carrier to utilize a time division duplex (TDD)mode.
 16. The system of claim 11, the carrier management module toaggregate another secondary carrier with the primary carrier and thesecondary carrier to further increase effective bandwidth for themulticarrier communications system.
 17. The system of claim 11, themulticarrier communications system comprising an orthogonal frequencydivision multiple access (OFDMA) system.
 18. A wireless client device,comprising: an antenna array; and a radio to connect to the antennaarray, the radio to receive primarily control information and limitedmedia information over a primary carrier defined with a first portion ofa radio frequency spectrum for use by a multicarrier communicationssystem, and receive primarily media information and limited controlinformation over a secondary carrier defined with a second portion ofthe radio frequency spectrum for use by the multicarrier communicationssystem, wherein the primary carrier and the secondary carrier areaggregated to increase effective bandwidth for the multicarriercommunications system.
 19. The wireless client device of claim 18,wherein the first portion of the radio frequency spectrum and secondportion of the radio frequency spectrum comprise contiguous radiofrequency spectrums.
 20. The wireless client device of claim 18, whereinthe first portion of the radio frequency spectrum and second portion ofthe radio frequency spectrum comprise non-contiguous radio frequencyspectrums.